The present novel concept broadly relates to the art of vehicle suspension systems and, more particularly, to an air spring assembly including an air spring, a sensor outputting a sensor signal, a valve operative to control fluid communication with the air spring, and a signal processing device communicating signals between the sensor and/or valve and a supervisory control unit. The present novel concept also relates to an operating module adapted for use in association with an air spring and including a sensor, a valve and a signal processing device. The present novel concept further includes a system and method utilizing such an air spring assembly and/or operating module.
Terms such as “process,” “processing” and “processor” are used herein in various forms and combinations to refer to conversion, translation, encryption, decryption, encoding, decoding and other actions or manipulations of signals, data, commands, instructions and/or communications, as well as components adapted to perform the same. As an example, an analog-to-digital processor may be used to convert an analog signal into a digital signal. As another example, a signal processing device may be used to encode or otherwise combine and/or convert a plurality of signals, such as digital sensor signals, for example, into a form suitable for communication on a vehicle or local network. Additionally, these terms are used herein to refer to the performance or execution of commands and/or instructions, such as those that might be received from a decision-making or supervisory device or system. For example, a signal processing device may be used to receive a command or instruction from another component or system, such as from along a vehicle or system network, for example, and perform, execute, or cause to be executed, that command or instruction, such as receiving an instruction to open a valve and energizing or otherwise signaling a component to energize the valve actuator, for example.
Terms such as “control” and “controller” are used herein in various forms and combinations to refer to actions or components for performing actions that involve evaluating or comparing inputs, signals, data and/or communications and making decisions or determinations regarding the actions based upon predefined criteria. For example, a supervisory control unit may receive height data from a plurality of height sensors and make one or more determinations and/or decisions based upon this height data, such as determining that the vehicle is not level, for example, deciding that a leveling action should be initiated and then issuing appropriate instructions to cause the corresponding suspension components to perform an action. A “processor” or “processing device,” as discussed above, might then receive the issued instruction and execute, perform or cause the instructed action to be performed.
As vehicle manufacturers strive to develop vehicles providing greater ride comfort as well as improved vehicle performance at these comfort levels, the various major mechanical systems of such vehicles have become increasingly electronically controlled and are now often quite complex. Such major mechanical systems can include suspensions systems having active damping and/or active roll control, braking systems that provide anti-lock braking and traction control, and stability control systems that often include aspects of one or more of the foregoing as well as other systems. Recently, even the headlights of a vehicle have become equipped with actively adjustable mounting systems. For example, some high-intensity lamp systems are operative to keep the lamp beams properly directed along the roadway as the vehicle body sways and tilts, such as under turning, braking or accelerating actions.
As the foregoing and other vehicle systems have become increasingly complex, a number of problems and/or difficulties have developed. One example of such a problem involves the attendant increase in the number of sensors and other components, as well as the corresponding increase in wires and/or connectors needed to communicate information and data to and from these devices. Direct or “hard” wiring such a multitude of sensors exacerbates or otherwise undesirably influences the existing challenges already associated with assembly and/or installation. Additionally, this can lead to an increase in cost and/or in vehicle weight.
Another example of such a problem involves the inevitable increases in computing/processing capacity that accompanies the increased usage of electronic components and systems. More specifically, the general need for increased processing power tends to lead to the use of microprocessors and attendant components in the systems that are greater in number, greater in size and processing power, or in many cases greater in both number and size. This, in and of itself, does not normally present an issue. Often, however, components for such systems are often housed within a common structure that is then mounted on the vehicle.
One such structure is often referred to as a body control module (BCM), which typically houses a collection of supervisory control units that have electronic components related to systems effecting body control (e.g., vehicle height control and active leveling). Typically, available physical space is at a premium on a vehicle and great efforts are also often made to avoid weight increases. Thus, it is increasingly difficult to fit larger and/or a greater number of processors and other components on or around the vehicle or within a housing, such as a BCM, without increasing the size of the same, which is undesirable. Furthermore, the corresponding weight increase from the additional materials used would likely be met with considerable resistance. Thus, the density of the electronic components fitted into this constrained physical space can increase the difficulty of assembly, and may even create corresponding increases in assembly costs.
Another problem associated with the use of increased processing power is the increased quantity of heat that is generated by the processors and components. This is particularly problematic where processors and components of various kinds and types are densely packaged within limited space. It is well understood that electronic components are generally adversely affected by operating at increased temperatures. Thus, continued operation in such an environment is disadvantageous. Additionally, increases in mass and/or surface area are often utilized to dissipate the additional heat load caused by the processors and components. As weight and physical space constraints are commonly present on vehicles, however, these options are often less acceptable.
In light of these and other problems and difficulties, vehicle suspension components and systems have been proposed that attempt to distribute electronic controllers or other decision making components to other parts of the vehicle to reduce space usage and heat loads, or to at least to help offset the trends discussed above regarding the same. One example of these kinds of components and systems is disclosed in International Publication No. WO 2005/032863 (the '863 publication). However, the components and system disclosed in the '863 publication suffer from certain deficiencies that may reduce the utility and application of the same.
More specifically, the components and system disclosed in the '863 publication have decentralized control (i.e., logic and decision making) of the vehicle suspension system. That is, each air suspension unit independently controls its operation and performance (e.g., height and damping rate adjustment) at its respective corner of the vehicle. The system does not appear to disclose any type of whole-vehicle electronic control unit (e.g., master or supervisory controller), such as might be located in a BCM, for example. Thus, there is no single component that receives and evaluates signals regarding overall vehicle performance and operation, and that is responsible for coordinating and directing the operation of the suspension components.
The air suspension units in the '863 publication are indicated as being in communication with one another. However, all decisions regarding performance and operation of an air suspension unit are believed to be independently made at each corner by the electronic controller at that corner. As a result, four different and independent logic processes, one at each corner, are being performed on the vehicle at any given time. Thus, it is believed that such a non-coordinated control scheme may result in suspension components reacting to changes induced or otherwise caused by the actions at other corners of the vehicle, rather than occurring primarily in response to road and/or performance inputs. Therefore, it is believed that significant difficulties with regard to performance and operation may develop due to the lack of a centralized or vehicle-centric control unit (e.g., a global chassis controller). For example, it seems possible that one front corner could be taking an action while the other front corner is taking a different action. These two actions might offset one another resulting in an unaddressed vehicle condition or cause some other undesirable result. As such, it is believed that the components and system disclosed in the '863 publication do not adequately address the foregoing problems and difficulties in present in known vehicles and vehicle suspension systems.